AstraZeneca's Imfinzi demonstrates benefit in combination with antibody

AstraZeneca reported on Friday that ‘Imfinzi’ and tremelimumab with chemotherapy demonstrated an overall survival benefit in the ‘POSEIDON’ trial for first-line stage four non-small cell lung cancer, making it the first phase 3 trial to demonstrate an overall survival benefit with tremelimumab.

The AIM-traded firm said Imfinzi plus chemotherapy, meanwhile, demonstrated a progression-free survival benefit, but a trend in overall survival did not achieve statistical significance.

It said POSEIDON was a phase 3 trial of Imfinzi, or durvalumab, plus platinum-based chemotherapy, as well as Imfinzi, tremelimumab and chemotherapy, versus chemotherapy alone, in the first-line treatment of patients with stage four metastatic non-small cell lung cancer.

Positive high-level results from the final analysis of POSEIDON showed the combination of Imfinzi, tremelimumab and chemotherapy demonstrated a statistically significant and clinically meaningful overall survival benefit versus chemotherapy alone.

The immunotherapy combination also demonstrated a statistically significant improvement in progression-free survival versus chemotherapy alone.

Patients in that arm were treated with a short course of tremelimumab - an anti-CTLA4 antibody - over a 16-week period in addition to Imfinzi and standard chemotherapy.

AstraZeneca said the Imfinzi plus chemotherapy arm demonstrated a statistically significant improvement in progression-free survival versus chemotherapy in the previous analysis, but the overall survival trend observed in the analysis did not achieve statistical significance.

Patients in the control arm were treated with up to six cycles of chemotherapy, while those in the experimental arms were treated with up to four cycles.

Each combination demonstrated an acceptable safety profile, and no new safety signals were identified.

The company said the combination with tremelimumab delivered a “broadly similar” safety profile to the Imfinzi and chemotherapy combination, and did not lead to an increased discontinuation of treatment.

“We are pleased to see the POSEIDON phase 3 trial demonstrate, for the first time, a significant and clinically meaningful overall survival benefit for Imfinzi plus tremelimumab with chemotherapy in metastatic non-small cell lung cancer,” said executive vice-president of the oncology business unit Dave Fredrickson.

“We were particularly pleased by the safety profile.

“We've seen encouraging uptake of novel combinations in this setting and believe this new approach will add a further option for patients with high unmet medical need.”

The data would be presented at a forthcoming medical meeting, AstraZeneca said.

At 0812 BST, shares in AstraZeneca were up 0.44% at 7,714p.